Define stable test tiers and risk-ranked journeys across installed
commands, public Python APIs and the `Qt` chart.
Also,
- keep volatile subsystem deats out of adjacent iface guides
- require real `Qt` input and protocol-faithful offline services
- specify lifecycle ownership, CI tiers and acceptance gates
(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))
